因台灣地震十分頻繁，過去曾發生水庫設施受震破壞之重大事件，國外亦有類似案例，故本研究對於台灣幾個主要土石壩，如永和山水庫、仁義潭水庫、曾文水庫及南化水庫等，利用佈設於壩體之地震儀所量測到的近二十餘年內地震記錄，做一系列之時域與頻譜之分析，如加速度歷時、速度歷時、位移歷時、傅氏譜、反應譜等，以找出土石壩受震之特性及不同土石壩之間趨勢的異同。研究結果顯示，在時間域分析上，加速度、速度、與位移反應，在壩頂的垂直壩軸向大多數都是最大的，而PGA、PGV與PGD在壩體上不同的位置及方向之間，亦具有明顯的相關性。在頻率域的分析上，壩的共振頻率與壩高具有一定程度的關係。 In Taiwan, Earthquakes happen very often, and some major damage has been found on the dams, either in the abroad. The author used the records of motion on some major earth dams in recent twenty years, including Tunghsing Dam, Jenyih Dam, Tsengwen Dam, and Nanhua Dam, to make some analysis in the time and frequency domain, such as producing acceleration history, velocity history, displacement history, fourier spectrum, and response spectrum. Then, the vibration characteristics of the analyzed earth dams could be identified. It shows that the responses of motion in time domain are the largest in transverse direction at the top of the dams. There are some significant correlations between PGA, PGV, and PGD in different directions and positions at the dams. In frequency domain, the resonant frequency of the dams seems to relate to their heights considerably.
